Table 5.

Possible binding sites of NSP9 against known anti-viral drugs

Drugs		Total binding sites			(6W4B) NSP9 Replicase of COVID-19
Grazoprevir	Known similar target molecule				NS3 protease, NS4a protein, Hepacivirus C
	Binding properties	1	1	Superposition type	L
				RMSD	0.94 Å
				Amino acid targets of drug	66 ILE 59 LYS 62 GLY
				No. of residues in known binding	16
				Human similar targets	8
Ribavirin	Known similar target molecule				RNA polymerase, Norwalk virus
	Binding properties	1	1	Superposition type	R
				RMSD	0.80 Å
				Amino acid targets of drug	36 THR 35 THR 34 ASN
				No. of residues in known binding	09
				Human similar targets	2
Rimantadine	Known similar target molecule				M2, BM2 protein, Influenza A,B
	Binding properties	3	1	Superposition type	L
				RMSD	0.90 Å
				Amino acid targets of drug	109 ALA 106 SER 105 GLY
				No. of residues in known binding	9
				Human similar targets	0
			2	Superposition type	R
				RMSD	1.10 Å
				Amino acid targets of drug	111 VAL 108 VAL 106 SER
				No. of residues in known binding	10
				Human similar targets	0
			3	Superposition type	R
				RMSD	1.26 Å
				Amino acid targets of drug	111 VAL 109 ALA 106 SER
				No. of residues in known binding	10
				Human similar targets	0
Tipranavir	Known similar target molecule				Protease, HIV-1
	Binding properties	1	1	Superposition type	L
				RMSD	1.21 Å
				Amino acid targets of drug	16 ALA 26 ASP 27 ASP
				No. of residues in known binding	27
				Human similar targets	3

Features of different drug binding motifs. HIV-1 Human Immunodeficiency virus 1, RMSD Root Mean Square Deviation, Å angstrom, ILE isoleucine, GLY glycine, VAL valine, ASP aspartic acid, ASN asparagine, ALA alanine, THR threonine, LYS lysine, SER serine